This invention relates to a frame structure for use in a vehicle seat back.
A rear seat before a trunk or luggage of a vehicle is generally comprised of a seat cushion having a lower part fixed to the floor of a passenger compartment and a seat back having a lower part supported on a rear part of the seat cushion. There are two types of seat backs, one being inclinable forward and the other being fixed to a vehicle body.
Such a seat back has, as shown in FIG. 7, a seat back frame structure 100 in which a peripheral frame member 102 is arranged along the periphery of a substantially rectangular panel frame member 101, and a pad and an outer trim are so provided as to cover the seat back frame structure 100.
In recent year, various measures have been studied to improve the safety of automotive vehicles. One essential point is to set a withstand load, which is exerted on the rear seat upon the movement of a luggage in the trunk at the back, at a specified value or higher. Motor-Vehicle Rule ECE No. 17 is known as a standard according to which a standard luggage having a weight of 18 kg and a colliding surface of 300 mm (vertical dimension)xc3x97300 mm (horizontal dimension) is brought into contact with the rear surface of the seat back by an inertial force.
The seat back frame structure of the conventional rear seat is constructed such that the peripheral frame member is arranged along the periphery of the panel frame member. Accordingly, when a large load acts on a substantially middle part of the seat back in a test conducted in accordance with the aforementioned motor-vehicle rule, there is the likelihood that the panel frame member is dented to project forward, and the rear seat is judged to lack the strength against the large load.
It is an object of the present invention to provide a seat back frame structure which is free from the problems residing in the prior art,
It is another object of the present invention to provide a seat back frame structure which has the strength against an external force exerted upon a possible movement of a luggage placed in a trunk of the vehicle.
According to an aspect of the present invention, a frame structure is used in a vehicle seat back, and comprises: a panel frame member having a substantially rectangular shape; a peripheral frame member arranged along the periphery of the panel frame member; and a reinforcing frame member having opposite ends coupled to an upper part and a lower part of the peripheral frame member; and an intermediate part corresponding to an external-force receiving portion of the panel frame member for receiving an external force resulting from a possible movement of a luggage placed in a trunk of the vehicle.
These and other objects, features and advantages of the present invention will become more apparent upon reading the following detailed description along with the accompanying drawings.